#include <stdlib.h>
#include <stdio.h>
#include <alsa/asoundlib.h>
      
int
main(int argc, char **argv)
{
	int i;
	int err;
	short buf[128];
	snd_pcm_t *playback_handle;
	snd_pcm_hw_params_t *hw_params;

	if ((err = snd_pcm_open (&playback_handle, argc > 1 ? argv[1] : "default", SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
		fprintf (stderr, "cannot open audio device %s (%s)\n", 
			 argv[1],
			 snd_strerror (err));
		exit (1);
	}
	   
	if ((err = snd_pcm_hw_params_malloc (&hw_params)) < 0) {
		fprintf (stderr, "cannot allocate hardware parameter structure (%s)\n",
			 snd_strerror (err));
		exit (1);
	}
			 
	if ((err = snd_pcm_hw_params_any (playback_handle, hw_params)) < 0) {
		fprintf (stderr, "cannot initialize hardware parameter structure (%s)\n",
			 snd_strerror (err));
		exit (1);
	}

	if ((err = snd_pcm_hw_params_set_access (playback_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
		fprintf (stderr, "cannot set access type (%s)\n",
			 snd_strerror (err));
		exit (1);
	}

	if ((err = snd_pcm_hw_params_set_format (playback_handle, hw_params, SND_PCM_FORMAT_S16_LE)) < 0) {
		fprintf (stderr, "cannot set sample format (%s)\n",
			 snd_strerror (err));
		exit (1);
	}

	unsigned int hw_rate = 44100; int hw_dir = 0;
	if ((err = snd_pcm_hw_params_set_rate_near (playback_handle, hw_params, &hw_rate, &hw_dir)) < 0) {
		fprintf (stderr, "cannot set sample rate (%s)\n",
			 snd_strerror (err));
		exit (1);
	}

	if ((err = snd_pcm_hw_params_set_channels (playback_handle, hw_params, 2)) < 0) {
		fprintf (stderr, "cannot set channel count (%s)\n",
			 snd_strerror (err));
		exit (1);
	}

	if ((err = snd_pcm_hw_params (playback_handle, hw_params)) < 0) {
		fprintf (stderr, "cannot set parameters (%s)\n",
			 snd_strerror (err));
		exit (1);
	}

	snd_pcm_hw_params_free (hw_params);

	if ((err = snd_pcm_prepare (playback_handle)) < 0) {
		fprintf (stderr, "cannot prepare audio interface for use (%s)\n",
			 snd_strerror (err));
		exit (1);
	}

	for (i = 0; i < 1024 * 2.5; ++i) {
		if ((err = snd_pcm_writei (playback_handle, buf, 128)) != 128) {
			fprintf (stderr, "write to audio interface failed (%s)\n",
				 snd_strerror (err));
			exit (1);
		}
	}

	snd_pcm_close (playback_handle);

	return EXIT_SUCCESS;
}
